Biology Textbook Questions (pg 11+)

1) Give 2 differences in structure between eukaryotic and prokaryotic cells. Eukaryotes have chromosomes in the nucleus, whereas prokaryotes have free-floating DNA strands. Eukaryotes have no slime capsule, but prokaryotes do.

2) An onion cell is viewed with x100 magnification and looks 7.5mm wide. What is the actual size of the cell in um? 7.5mm / 100 = 0.075mm x 1000 = 75um

3) Why might you add stain to a microscope slide? To allow the sample to be seen easier.

4) Phloem tubes transport food up and down a plant. Give a feature that makes it specialised for that function. It has little internal structure and instead relies on companion cells for energy.

5) Describe how a root hair cell is specialised for its function. It has a large surface area to absorb nutrients and a large permanent vacuole to store water inside.

6) Describe the events in the cell cycle that need to occur before mitosis can begin. Ribosomes and mitochondria are produced; chromosomes double.

7) Give 2 things that help to increase the rate of binary fission. Nutrients, Warmth

8) A bacteria has a division time of 30mins. How many will there be after 3h? 30min = 2, 60min = 4, 90min = 8, 120min = 16, 150min = 32, 180min = 64

9) a) Which antiseptic was most effective? A

b) What is the inhibition zone for antiseptic C? 4.5mm x 4.5mm = 20.25mm 20.25mm x Pi = 62.775 = 63mm squared

c) Describe a control that could’ve been used. Another agar plate with no antiseptic.

d) Why should a control be used? To ensure no anomalies and get comparable results.